Technical help.. missing power!

Hi Guys,

I'd welcome some thoughts and suggestions on my current "blip" with my 3200. It is running sweetly, but is down on power. I'll try and list as clearly as possible what has happened, and what I have done since having the car in my ownership. If anybody has any suggestions as to what could be the problem I'm all ears!

1) On purchase I did a full service, oil/filters/plugs.
2) Dodgy throttle pedal pot was causing the car not to go to full throttle. Fixed.
3) Started getting CEL's pointing finger at lambda sensors and knock sensors.
4) Replaced knock sensors.
5) Flushed fuel system with Redex.
6) Battery + Throttle pedal reset.
7) Checked Pierburg valve and cleaned connectors.

Since doing all of this I'm not getting the lambda sensor CEL's anymore. In fact I have no errors at all in the computer.
Things I've noted..
1) I can hear the turbos spooling up.
2) There's no oil in the air intake system anywhere.
3) Not losing any oil or water.
4) Once warmed a little the engine sits a perfectly constant 900rpm at idle.
5) When hot oil pressure is just under 4bar at idle.

Potential pointers..
1) If I've been trundling around town for a while, then the first time I give it "the beans" and wide open throttle I do get a little bit of black smoke, but then no more after that. My previous 3200 was the same in this regard so I'm guessing that it's just some unburnt fuel or something and a characteristic of the engine design.
2) I get quite a loud "deflated whistle" (think R2D2 passing on!!) from the turbo system when I back off the throttle at lower speeds after giving it quite a bit of throttle. When releasing the pedal I here a typical "psst" kind of dump valve sound, but there's this second longer whistle that I never remember my previous 3200 doing.
3) The engine just feels flat between 3k and 5k rpm, when it hits 5k you get a second kick in the back like you would on a variable valve time engine.

My previous 3200 was a pre-OBCD2 year 2000 car (Gen 1?) and my current one is a 2001 OBCD2 (Gen 2?) car which does seem to have subtly different plumbing under the bonnet.

So.. I'm guessing I either have an air leak somewhere.. OR.. the lambda sensors are playing up, but not enough to log an error?

So, to recap, it's running perfectly.. no misfires, smooth, responds well, revs to the redline, but feels flat between 3k and 5k RPM... just doesn't go like a 400bhp Italian car ought to! I did a rough 0-60 test on a dry road in sport mode.. had no ASR flashing and only did it in around 7 seconds. Not very scientific but it ought to be a darn sight better than that!

The fact I can hear the turbos and there's no oil in the intake system, nor is the smoke pouring out anywhere leads me to believe they are alive and well and doing what they should be doing. The whistling and lambda CEL leans me towards a leak or a sensor issue. However I don't have any CEL's currently and the whistling only occurs when lifting off...

So.. over to the experts??!

Cheers

Mark

Have you checked the condition of the intercoolers? They may be a little prone to stone damage due to their location. I'm wondering if the second round of air dumping/whistling is caused by a small hole in one of them. That would drop boost pressure more gradually than a split turbo hose. It could also account for the black smoke as it might cause over fuelling if the engine is expecting more air.

Hi Trev,

I've not considered them. However I would have thought if that were the case I'd get some black smoke all the time I planted my foot. Not once in a while and only after prolonged town "burbling"?

I've currently only got an OBD2 reader that allows me to clear codes as my USB cable for the laptop is the wrong protocol type. I've ordered the right cable now so hopefully this week I can get some live running data off the car to see if there's anything that gives an clues...

Cheers

Mark

Trev Latter said:

Have you checked the condition of the intercoolers? They may be a little prone to stone damage due to their location. I'm wondering if the second round of air dumping/whistling is caused by a small hole in one of them. That would drop boost pressure more gradually than a split turbo hose. It could also account for the black smoke as it might cause over fuelling if the engine is expecting more air.

Click to expand...

I was going to suggest the same thing, a SMALL hole but maybe in one of the hoses which only really has any effect under heavy load.
Is there any misfiring at all? If so, check for good connections around the throttle body

Hi Stuart,

Nope, no misfiring. Runs perfectly smooth.. If somebody told you it was a car with 250hp you'd think nothing was wrong.

Cheers

Mark

I had a similar issue with my 3200, it was the hoses leaking air and causing the turbos not to spool as they should. Was still quick just not silly quick.

Hi Outrun,

Ok I'm begining to lean towards some kind of leak too.. however all the hoses for the turbos are buried under the V of the engine so a bit of a b!tch to get to and check without some ramps yes?

Cheers

Mark

mchristyuk said:

Hi Outrun,

Ok I'm begining to lean towards some kind of leak too.. however all the hoses for the turbos are buried under the V of the engine so a bit of a b!tch to get to and check without some ramps yes?

Cheers

Mark

Click to expand...

The map sensor hose cones from under the plenum. The others are for coolant. The turbo/inlet hoses run around the outside of the engine, somer are hard to get to.

You may have a plenum to head o ring passing; mine were very flat and fell appart when I took them out. If the knock sensors were changed and these weren't it would be worth looking. That said if a jubilee clip wasn't tightened on one of the three Take offs from the plenum it could easily be Taft. You can get to two if the on the back of the plenum if you are very careful....

It's sounds like a boost leak to me as the engine revs fine but just doesn't have the oomph which let's face it in these cars is provided by the twins. I would start by checking the Pierburg valve again and then all turbo hoses. Spray contact cleaner on or around the bullet connector on thr valve itself as they are known for poor electrical connections

Look at the other thread on here which details the car being down on power and it came down to this boost valve. I have recently replaced mine after it was over boosting.

Almichie.. we have a winner. I owe you some beer tokens

Had a search around under the bonnet to see if I could spot anything obvious and every single "small diameter" pipe connecting to the engine (bar one) had no kind of retainer clip around them where they connect to the various sections (plenum, t pieces, etc..). I had a quick look on Eurospares for the engine diagrams and every single one should have had a jubilee clip (or similar) on them.

So I went to the toolbox and went at the engine with a small army of tie wraps. I think I did about 10 connections in the end.

Just been out for a blast and it feels much better. It still plays musical tunes behind the bulkhead somewhere when I lift off the accelerator (which I swear my old 3200 didn't do!), however it has got rid of the flat spot between 3k and 5k and there isn't the "step" at 5k.. instead it just pulls harder and harder as the revs increase.

Whether that is all the possible leaks sorted I don't know.. however it is going much better and I timed a rough 0 to 60 at around 5.75 seconds.. and seeing as the auto is supposed to do it in 5.5 I'd say its looking much healthier now!

Contigo, I did have that valve out today and clean the connectors.. what I didn't pay attention to was all the missing retainer clips!

Cheers

Mark

mchristyuk said:

Almichie.. we have a winner. I owe you some beer tokens

Had a search around under the bonnet to see if I could spot anything obvious and every single "small diameter" pipe connecting to the engine (bar one) had no kind of retainer clip around them where they connect to the various sections (plenum, t pieces, etc..). I had a quick look on Eurospares for the engine diagrams and every single one should have had a jubilee clip (or similar) on them.

So I went to the toolbox and went at the engine with a small army of tie wraps. I think I did about 10 connections in the end.

Just been out for a blast and it feels much better. It still plays musical tunes behind the bulkhead somewhere when I lift off the accelerator (which I swear my old 3200 didn't do!), however it has got rid of the flat spot between 3k and 5k and there isn't the "step" at 5k.. instead it just pulls harder and harder as the revs increase.

Whether that is all the possible leaks sorted I don't know.. however it is going much better and I timed a rough 0 to 60 at around 5.75 seconds.. and seeing as the auto is supposed to do it in 5.5 I'd say its looking much healthier now!

Contigo, I did have that valve out today and clean the connectors.. what I didn't pay attention to was all the missing retainer clips!

Cheers

Mark

Click to expand...

Good news Mark! Glad you got it sorted with a few pointers from people who have had a similar experience. These beasts actually aren't all that hard to work on, just a little familiarisation is all that's needed.

Great news and a cheap fix. Ta for sharing the results.

Well done Al and Mike!

Mark, Check the brake servo for the wistling sound,you can hear it under the pedel area inside the car,maybe the one way valve has failed and your getting boost to the servo

Mine's down on power too,valve timing on the rear chains is incorrect and has been since new!

Dave

Did you check the large cover on the underside of the plenum was secure and the seal looked ok? unfortunately you have to remove the plenum to check this but these come loose quite regularly and need new seals and loctite on the screws. i also replaced the plenum to head o-rings as these do not like being re-used.

Dave,

Will take a look at the brake servo as suggested. Though not today.. weather is appalling down here and don't fancy crawling about on the driveway today

Davy, personally I haven't, though I believe the idle would be inconsistent if there was a leak there and my idle is spot on?

Cheers

Mark

Sorry a bit off topic. My idle ia high above 1000rpm and alighlty hunting. Anyway to adjust it? i m sure yhe penlum cover is tight after replacing the starter.

timkee330ci said:

Sorry a bit off topic. My idle ia high above 1000rpm and alighlty hunting. Anyway to adjust it? i m sure yhe penlum cover is tight after replacing the starter.

Click to expand...

Sounds like an air leak, the throttle pot or throttle body at fault. They do hunt a little when cold and usually settle once warmed up. Try flicking the throttle pedal, see if this stops the hunting, my throttle pedal was dead and flicking it stopped the hunting.

Yep DBW system could be a problem usually TB if a little too hunty at idle but most 3200 do that hunting when cold.

Glad you found it Mark.